Non-obese Boys Research Articles

Genetic polymorphisms (FTO rs9939609 and TMEM18 rs6548238), adipokines (leptin and adiponectin) and adiposity in children and adolescents with asthma

ObjectiveTo describe independent factors related to the interaction of FTO rs9939609, TMEM18 rs6548238, leptin, and adiponectin in children/adolescents with asthma, under the influence of obesity. MethodsThe authors performed a cross-sectional study with 57 children/adolescents, ages 8–19 years, at a tertiary hospital, from 2017 to 2018. Participants were classified by nutritional status, performed spirometry with a bronchodilator test and completed an asthma questionnaire, higher scores indicated more asthma symptoms. Two asthma groups were formed: Group 1(G1)-normal-weight; Group 2(G2)-overweight/obese. Serum was collected for adipokines (n = 32) and genetic polymorphisms (n = 53) dosages. ResultsAge and body mass index (BMI) correlated directly in normal-weight (p = 0.009) and obese participants (p = 0.004). Girls reported more asthma complaints (p = 0.044). Participants with negative bronchodilator responses presented lower BMI (14.55–17.16) than responders (19.4–26.84) (p = 0.049). Leptin dosages are related directly to BMI (5,34–40 ng/ml in obese × 0,54–42 ng/ml in nonobese) (p = 0.003). Levels were high in girls (4.78–17.55 µg/ml) (p = 0.029) and low in nonobese boys (0.54–6.92 µg/ml) (p = 0.006). In obese, low leptin levels (< 10 ng/ml) were found in small airway dysfunction carriers (p = 0.025); elevated adiponectin (> 5 µg/ml) correlated with FEV1/FVC > 80 % (p = 0.035) and positive bronchodilator tests (8.84–13 µg/ml) (p = 0.039); and FTO A allele correlated with low adiponectin 0–8.84 µg/ml (p = 0.021) and low FEV1/FVC (46 %-88 %) (p = 0.023). ConclusionBMI correlated directly with age and leptin levels. Obese participants presented high serum levels of leptin and FTO A allele correlated with low FEV1/FVC. Larger cohorts are necessary for better elucidation of the role of adipokines and polymorphisms in the pathophysiology of asthma and obesity.

Lower Circulating Sertoli and Leydig Cell Hormone Levels During Puberty in Obese Boys: A Cross-sectional Study.

Alterations in semen characteristics and circulating Sertoli and Leydig cell hormones have been described in obese male adults. Whether hormonal alterations occur before adulthood has not been fully evaluated. We describe circulating Sertoli and Leydig cell hormone levels in overweight-obese (ow/ob) boys through childhood and adolescence in a cross-sectional study. Monocentric study in the Pediatric Endocrinology Unit of Angers University Hospital. Three hundred and fifty-one obese and overweight boys aged 5-19 years underwent physical examination, dual-energy X-ray absorptiometry for body composition, oral glucose tolerance test on insulin and glucose, and measurements of follicle-stimulating hormone, luteinizing hormone, anti-Müllerian hormone (AMH), inhibin B, testosterone, and estradiol. Hormonal levels were compared with normative data obtained from 652 healthy nonoverweight nonobese boys of similar age or Tanner stage. Median inhibin B and testosterone levels during puberty were significantly lower in ow/ob than in healthy boys (1) from age >12 years and thereafter for inhibin B, and (2) from age >14 years and thereafter for testosterone. At Tanner stages 4 and 5, 26%, 31%, and 18% of inhibin B, testosterone, and AMH values were below the 5th percentile in ow/ob subjects (P < .01). In multiple regression analyses, estradiol and total bone mineral density Z-score were negative predictors of inhibin B, fat mass percentage was a negative predictor of testosterone, and insulin was a negative predictor of AMH. Lower Sertoli and Leydig cell hormone levels during puberty were observed in the ow/ob boys.

Autism Spectrum Disorder in Pediatric Idiopathic Intracranial Hypertension

In recent years, the substantial burden of medical comorbidities in autism spectrum disorder (ASD) populations has been described. We report a retrospective observational case series of pediatric patients with suspected idiopathic intracranial hypertension (IIH) and concurrent ASD. Pediatric subjects with suspected IIH aged 2–18 years were identified by review of a pediatric neuro-ophthalmologist’s database spanning from July 1993 to April 2013. ASD diagnoses were identified within this cohort by an ICD-9 diagnosis code search and database review. Three subjects had concurrent ASD diagnoses; all were non-obese males. Since the retrospective observational case series was performed in April 2013, we identified three additional IIH cases in boys with ASD. Our experience suggests that IIH may be a comorbidity of ASD, particularly in non-obese boys.

Obesity and decrease of daily physical activity among children and adolescents: a follow-up study

ABSTRACT We analyzed the effect of obesity on daily physical activity (DPA), light-intensity physical activity (LPA), moderate-intensity physical activity (MPA) and vigorous- intensity physical activity (VPA) in children and adolescents. Overall, 462 students from a public school (53.6% boys; aged 7-12 years) were involved in this one-year longitudinal study. Physical activities and sedentary behaviors (SB) were reported in the questionnaire Food Intake and Physical Activity of Students (Web-CAAFE). Obesity was evaluated through Body Mass Index (BMI z score ≥ 2). Obesity was observed in 16.5% of participants, but it did not influence LPA, MPA or DPA. However, VPA were 20% less frequent among obese students (β2=0.80; CI 95%: 0.66-0.98). Obese girls showed less frequency of VPA than non-obese boys (Mean Difference = -0.97; CI 95%: -1.36 to -0.57). Non-obese girls showed less VPA than non-obese boys (Mean Difference = -1.18; CI 95%: -1.40 to -0.95) and obese ones (Mean Difference = -0.57; CI 95%: -0.90 to -0.24). Obese boys showed fewer VPA, if compared to non-obese ones (Mean Difference = -0.61; CI 95%: -0.96 to -0.26). The analysis of the obesity-sex-age interaction showed a greater reduction in VPA among obese girls aged 10 years or more when compared to obese girls aged 7-9 years, and among boys obese and non-obese regardless of age. Amounts of VPA and SB increased simultaneously among non-obese boys and non-obese children aged 7-9 years. Obesity reduced VPA in the sample during the follow up of one year, independently of age and SB.

Effect of obesity on pulmonary function test in adolescent boys

Background: Obesity is an emerging problem, especially among adolescents due to their lifestyle changes related to the low level of physical activity and high-calorie diet. Excess adipose tissue is often associated with respiratory abnormalities such as a reduction in lung volumes, capacities, and expiratory flow rates. Hence, there is a need to find the pulmonary functions test values among obese adolescents and create awareness of the drawbacks of obesity as this is the high-risk period for the onset of obesity which predicts body mass index in adulthood. Aims and Objectives: The aims of the study were to study the effect of obesity on pulmonary function test (PFT) values in adolescent boys. Material and Methods: PFT was done on 10 obese and 10 nonobese adolescent boys of the age group 12–17 years from Dr. Ulas Patil English Medium School, Bhusawal. Forced vital capacity (FVC), forced expiratory volume at 1st s (FEV1), (FEV1/FVC) ratio, and maximum voluntary ventilation (MVV) were taken as parameters for study. Results: FVC, FEV1, FEV1/FVC, and MVV are reduced in obese subjects as compared to nonobese boys and it is statistically highly significant. Conclusion: Results of the study conclude that obesity affects the pulmonary functions and obese adolescents have significantly lower pulmonary functions.

Boys with Obesity have Attenuated Cardiorespiratory Fitness Independent of Fat Mass

PURPOSE: The assessment of cardiorespiratory fitness using ratio scaling to total body mass (TBM) is confounded by fat mass in obese populations because fat tissue does not contribute to oxygen utilization during exercise. Our objective was to isolate the independent effects of obesity on fitness when normalized to total lean body mass (TLM) and leg lean mass (LLM). We tested the hypothesis that boys with obesity would have attenuated cardiorespiratory fitness compared to age-matched non-obese boys. METHODS: Values are expressed as means ±SD with significance set at P<0.05. Seventeen non-obese boys (10.6±0.9y, 141.8±6.5cm, 35.5±7.0kg, 24±5% body fat) and thirteen age-matched obese boys (10.6±1.4y, 146.3±10.6cm, 60.25±13.0kg, 44±2% body fat) completed a cardiorespiratory fitness test (VO2peak) and body composition scan (DXA). RESULTS: Utilizing a 2-tailed independent T-test, both groups had comparable VO2peak test times (9.1±1.4 min; P=0.80), and peak heart rates (187±12 bpm; P=0.50). Boys with obesity had a reduction in VO2peak when normalized to TBM (54% of age-matched boys without obesity); however, this effect was reduced less when compared to LBM (76%) and LLM (68%). Further, simple linear regression found that total body fat accounted for 69% variance for mL/kgTBM/min, 49% variance for mL/kgLBM/min, and 40% variance for mL/kgLLM/min. CONCLUSIONS: These data indicate that obesity in young boys impairs cardiovascular fitness which supports the concept that obesity in pediatrics reduces aerobic capacity, which may have later life consequences in regards to cardiorespiratory fitness and all-cause mortality. Lastly, we show that the normalization of VO2 to LBM and LLM can provide an independent measure of fitness.

A15410 Cardiometabolic risks clustering associated with impaired bone mass in central obese children

Objectives: An increasing evidence has supported the association of bone mass with obesity and cardiometabolic risks. However, the combined contribution of obesity and cardiometabolic risk clustering to the bone mass remains unclear. Methods: A total of 8,780 participants, 6–18 years old were studied using data from a cross-sectional study conducted in urban Chinese cities in 2013–2014. Total body bone mineral content excluding head (BMCEH), total body lean mass, total and regional body fat were measured by dual-energy x-ray absorptiometry. Cardiometabolic indices, including blood pressure, fasting glucose, triglyceride and high-density lipoprotein were obtained. Participants were classified into four groups according to their cardiometabolic and obesity status, which were defined by the presence/absence of more than 2 abnormalities and with/ without excessive total body fat percentage (FMP) or android-to-gynoid fat maratio (AGR). Results: In boys, after controlling for age, height and lean mass, FMP, AGR, triglyceride and glucose were negatively associated with BMCEH, while high-density lipoprotein were positively associated with BMCEH (all p < 0.05). Similar relationships were also observed in girls, except for that with FMP (r = 0.142, p < 0.001) and glucose (r = −0.016, p = 0.318). Compared with cardiometabolic healthy non-obese boys, decreased levels of BMCEH were found in cardiometabolic healthy and unhealthy obese individuals, irrespective of obese status defined by FMP or AGR. In girls, similar patterns were only found in AGR defined obesity. For FMP defined obesity, cardiometabolic healthy obese girls demonstrated higher BMCEH than their healthy non-obese counterparts. Conclusion: Being obese with cardiometabolic abnormalities, particularly with central obesity may adversely influence bone mass in children.

Sexual dimorphism in interleukin 17A and adipocytokines and their association with insulin resistance among obese adolescents in Yogyakarta, Indonesia.

Pro-inflammatory cytokines interleukin 17A (IL-17), leptin, and adiponectin have been associated with obesity and insulin resistance. Moreover, differences in sex and ethnicity as well as plasma concentration of adipocytokines and cytokines have been associated with the risk of insulin resistance. This study was conducted to elucidate whether sex differences exist in the risk of insulin resistance in Indonesian adolescents and to determine how plasma leptin, adiponectin, and IL-17 predict insulin resistance. The study participants were 69 obese-overweight boys, 53 obese-overweight girls, 59 non-obese boys, and 50 non-obese girls aged 15-18 years. Insulin resistance was determined using the homeostatic model assessment of insulin resistance index. Plasma IL-17, leptin, and adiponectin were measured using ELISA. Data were analysed using one-way ANOVA and linear regression analysis. Odd ratios [ORs; 95% confidence intervals (CIs)] were analysed to estimate the risk of insulin resistance; the significance level was set at 95%. The OR (95% CI) for insulin resistance was higher in obese-overweight boys than in obese-overweight girls. The plasma IL-17 was higher in boys, whereas plasma adiponectin and leptin were significantly higher in girls. In all participants, obesity status and plasma leptin were the most efficient predictors of insulin resistance, whereas the IL-17 could not significantly predict insulin resistance. Sexual dimorphism exists in IL17 as well as leptin and adiponectin in adolescents. Plasma IL-17 cannot be used to predict insulin resistance in adolescents of both sex.

Obesity and secondary sexual maturity in boys

Background Obesity induces earlier secondary sexual maturity in girls. However, results of studies in boys have been inconclusive.Objective To assess for an association between obesity and sexual maturity in boys.Methods This was a prospective cohort study on 133 obese and 133 matched-for-age, non-obese, prepubertal boys, aged 9 to 10 years. They were observed every 4 months for a two year period. Obesity was defined as the BMI ≥the 95th percentile, according to the Centers for Disease Control 2000 growth charts. Secondary sexual maturity was defined as testicular volume of ≥4 mL and Tanner staging of pubic hair of ≥P2. Two trained nurses and a pediatric resident collected the data.Results By the end of the study period, 106 (79.7%) obese boys had attained a testicular volume of 4 mL or more, vs. 85 (63.9%) non-obese boys (RR 1.78; 95%CI 1.19 to 2.67; P=0.004). Furthermore, 81 (60.9%) obese boys attained pubic hair states of Tanner stage P2 vs. 37 (27.8%) non-obese boys (RR 1.85 95%CI 1.46 to 2.34; P&lt;0.001). The mean durations for achieving testicular volume of ≥4 mL were 21.25 (95%CI 20.75 to 21.74) months in obese boys and 22.26 (95%CI 21.80 to 22.72) months in non-obese boys (P=0.007). The mean durations for achieving Tanner stage P2 were 17.04 (95%CI 16.44 to 17.63) months in obese boys and 20.87 (95%CI 20.05 to 21.68) months in non-obese boys.Conclusion Obesity is associated with earlier onset of sexual maturity in boys.

Timing of moderate-to-vigorous exercise and its impact on subsequent energy intake in young males

Exercise can suppress appetite and energy intake but the impact of the timing of exercise remains unknown. Knowing that orexigenic hormone levels decrease during exercise but rapidly increase afterward, the aim of the current study was to investigate whether energy intake is increasingly reduced when exercise immediately precedes a meal compared to when a delay occurs between the exercise and the meal. Non-obese boys (15-20 years old; N=12) were individually evaluated while performing two randomly assigned experimental visits: 1) a 30-min exercise session of moderate-to-vigorous intensity followed immediately by an ad libitum buffet at 12 PM and 2), an identical session followed by a 135-min waiting period and an ad libitum buffet-type meal at 12 PM. In both conditions, a snack in the afternoon and a second ad libitum buffet-type meal at 5 PM were served. Findings showed that hunger ratings were similar under both conditions. The exercise session immediately prior to the meal compared with the condition with a >2h delay led to reduction of 11% and 23% in overall and lipid energy intakes at lunch, respectively (P-values>0.05). No significant differences were found in the energy intakes from the afternoon snack and dinner. Apart from lipids at lunch, the proportions of energy from the various macronutrients at each meal were similar. This study reveals that being physically active before a meal plays a role in acute energy intake reduction when a shorter delay is present between exercise and a meal. In addition, the absence of compensation over several hours is noteworthy.

Measurement Properties of Radial and Tibial Speed of Sound for Screening Bone Fragility in 10- to 12-Year-Old Boys and Girls

The objective of this study was to analyze measurement properties of the radial and tibial speed of sound (SoS) evaluated by quantitative ultrasound (QUS) for screening bone fragility. Bone fragility was defined as low whole body less head bone mineral density (WBLH BMD) measured by DXA (first tertile, 95% CI −1.1 to −0.9) and as past fractures evaluated by questionnaire. The sample included 319 nonobese boys and girls, ages 10–12 yr. All bone variables were standardized. The results revealed concordance coefficient correlations between WBLH BMD and radial and tibial SoS of 0.129 and 0.038, respectively. The regression lines between DXA and QUS variables were different from the identity lines. Cross-classification analysis by Kappa statistic showed that only 34% and 36% of the 113 participants categorized in the first tertile of WBLH BMD were also categorized in the first tertile of tibial and radial SoS, correspondingly. Logistic regression with gender and maturity adjustments demonstrates that radial SoS was the single significant variable in predicting OR for identifying participants with past fractures. In conclusion, the radial QUS revealed itself to be a valuable tool for screening bone fragility in youth of 10–12 yr, despite the absence of agreement with DXA WBLH BMD.

Responses of Obese and Non-obese Boys Cycling in the Heat

This study compared rectal temperature (Tre), heat sensation and sweating between obese and non-obese boys during cycling in the heat. Participants (aged 12-15 years) were 17 obese and 16 non-obese (BMI=29.4±4.3 and 16.8±1.7 kg · m⁻², respectively) boys. They cycled for 30-min (50-55% VO(2peak)) in a climatic chamber (35°C, 45% RH) and Tre, heat sensation and sweat volume were monitored. From the start to the end of cycling, Tre was similar between the obese (37.4±0.3-37.8±0.3°C) and non-obese (37.3±0.2-37.9±0.2°C) groups. Heat sensation was higher in the obese group from the start (3.6±2.7 vs. 1.3±1.4 cm; P=0.008) to the end (7.6±2 vs. 5.2±2.2 cm; P=0.003) of cycling. Sweat volume corrected by body surface area was similar between the obese (200±123 mL · m⁻²) and non-obese (212±80 mL · m⁻²) groups. Initial and final HR were similar in both groups, and RPE was higher in the obese group at 25th (P=0.040) and 30th (P=0.019) min. In conclusion, the obese pubescent participants presented similar Tre and sweating volume, but higher heat sensation while cycling in the heat.

The effect of obesity on testicular function by insulin-like factor 3, inhibin B, and leptin concentrations in obese adolescents according to pubertal stages

Objectives The aim of the present study is to investigate the effect of obesity on testicular function by evaluating reproductive hormones, inhibinB, insulin-like 3(INSL3), and leptin, in obese and non-obese adolescents according to pubertal Tanner stages. Design and methods Eighty adolescent boys were grouped ( n = 20) as; Group1: obese-Tanner2, Group2: non-obese-Tanner2, Group3: obese-Tanner4, Group4: non-obese-Tanner4. Serum INSL3, luteinizing hormone, follicle-stimulating hormone, total testosterone, free testosterone, estradiol, sex hormone binding globulin, inhibin B and leptin levels were assessed in all groups. Results INSL3 levels were significantly lower in obese adolescents compared to non-obese boys ( p = 0.003, Tanner2) and ( p = 0.031, Tanner4). There was a negative correlation between INSL3 and leptin ( r = −0.468, p = 0.001). The negative correlation between INSL3 and BMISDS indicates that pubertal obesity leads to Leydig cell impairment. Conclusions This study demonstrated for the first time in the literature that obesity effects testicular Leydig cell function starting from Tanner stage 2.

Role of insulin resistance in non-obese adolescents.

Insulin resistance in the obese is closely related with cardiovascular diseases and their risk factors not only in adults but also in children and adolescents. We aimed to elucidate whether insulin resistance in non-obese adolescents is related with these conditions. A total of 74 non-obese high-school students (38 boys and 36 girls) were recruited. Anthropometry, blood pressure, fasting serum chemistry and insulin activity were measured. Subjects with a homeostasis model assessment-insulin resistance (HOMA-IR) level greater than the 75th percentile (> 2.25 for boys and > 2.89 for girls) were defined as insulin resistant. Non-obese boys with impaired insulin sensitivity had higher systolic blood pressure, lower HDL-cholesterol concentration, and fewer hours of vigorous exercise during weekdays, while non-obese girls with impaired insulin sensitivity had higher systolic blood pressure than their peers with normal insulin sensitivity. By multiple stepwise regression analysis, systolic blood pressure (p < 0.001) and the hours of vigorous exercise during weekdays (p < 0.03) were independently associated with HOMA-IR in boys, while systolic blood pressure (p < 0.0001) and serum concentrations of HDL-cholesterol (p < 0.01) were found in girls. In nonobese adolescents, insulin sensitivity is related with cardiovascular risk factors.

Obesity Does Not Decrease the Accuracy of Testicular Examination in Anesthetized Boys With Cryptorchidism

Given that the prevalence of childhood obesity is increasing in the United States, we tested the timely hypothesis that obesity hinders physical examination based localization of the cryptorchid testis. Body mass index and percentiles of weight for height and body mass index for age were calculated for boys undergoing surgery for cryptorchidism at the University of California San Francisco Children's Hospital and Children's Hospital of Oakland. Two definitions of obesity were examined, ie greater than 85% or greater than 95% for either percentile. Patients were examined in the office and under general anesthesia before the skin incision. Intraoperative testicular location was recorded for each patient. The numbers of correct and incorrect preoperative determinations of testicular location were stratified by weight classification. Results were analyzed using contingency tables and Fisher's exact test. A total of 161 boys were recruited, accounting for 171 testes. The predictive value of palpating a suspected testis preoperatively with patients under anesthesia was greater than 95% for all weight classifications (p <0.0001). The predictive value of not palpating a testis preoperatively under anesthesia was greater than 56% for obese boys and greater than 42% for nonobese boys (p <0.0001). The concordance rates between examinations in the office and those performed under anesthesia were 90.9% and 82.7% for obese and nonobese boys, respectively (p = 0.51). The predictive value of not palpating a suspected cryptorchid testis in the office was higher in nonobese boys than in obese boys (81% vs 22%, p <0.0001). In our series childhood obesity did not make preoperative testicular examinations under anesthesia less accurate. However, office examinations may be more accurate in nonobese boys.

Cardiovascular Fitness in Obese Versus Nonobese 8–11-Year-Old Boys and Girls

The purpose of this study was to compare cardiovascular fitness between obese and nonobese children. Based on body mass index, 118 were classified as obese (boys [OB] = 62, girls [OG] = 56), while 421 were nonobese (boys [NOB] = 196, girls [NOG] = 225). Cardiovascular fitness was determined by a 1-mile [1.6 km] run/walk (MRW) and estimated peak oxygen uptake (VO2peak) and analyzed using two-way analyses of variance (Gender x Obese/Nonobese). MRW times were significantly faster (p < .05) for the NOB (10 min 34 s) compared to the OB (13 min 8 s) and the NOG (13 min 15 s.) compared to the OG (14 min 44 s.). Predicted VO2peak values (mL·kg-1·min-1) were significantly higher (p < .05) for the NOB (48.29) compared to the OB (41.56) and the NOG (45.99) compared to the OG (42.13). MRW was compared between obese and nonobese participants on the President's Challenge (2005), the National Children and Youth Fitness Study, and FITNESSGRAM® HFZ standards. The nonobese boys and girls scored higher on all three, exhibiting better cardiovascular fitness as compared to obese counterparts.

Elevated Fasting Insulin And Crp Levels Are Linked With Obesity And Low Aerobic Fitness In Young Qatari Boys.

There is a concern around the world, including the Arabic countries, of young people's lifestyle and its effect on health later in life. Early markers for a possible elevated risk to develop metabolically related chronic diseases are sought for but it is still unknown which of them is the most sensitive. Moreover, the primary life style factor focused on, has been nutrition and overweight with only little attention being paid to physical inactivity and low maximal oxygen uptake. PURPOSE: To screen for a large number of "metabolic" markers in the blood in young Qatari boys with concomitant measures of body composition and maximal oxygen uptake. METHODS: Forty, 10-13 years old boys were studied. A fasting blood sample was taken and in addition to their height and weight a DEXA scan was used to assess body composition. A step test was performed to exhaustion to measure aerobic fitness. RESULTS: The BMI ranged from 14 to 36 kg/m2 with a mean of 22 kg/m2 (median 20) and the aerobic fitness ranged from 14 to 36ml/kg/min with mean value of 30 ml/kg/min (median 32). Equally strong and significant correlations were found for both BMI and aerobic fitness and fasting insulin level with a four fold difference comparing the 20% "worst" and the 20% "best" (4 vs16 microU/ml. The 20% in the middle were in between (8 microU/ml). Also the CRP levels were significantly correlated with BMI and aerobic fitness, with a slightly stronger link to BMI. However the difference in absolute values between those with the highest and lowest BMI and aerobic fitness was 4 fold (2 vs 8 mg/l) and with the middle group being similar to the fit and non-obese boys. The pattern and strength for the correlations were the same for fat % and BMI. No relationships were found for measures of body composition and aerobic fitness to any of the other markers studied (chol, LDL- and HDL-chol, TG, glucose, HbA1c, homocysteine). CONCLUSIONS: Fasting insulin and to some extent CRP may be sensitive early markers of an emerging metabolic deterioration but in this group of boys it is impossible to dissociate between overweight and a low aerobic fitness playing the largest role. Longitudinal studies are needed to track the long term effect of these factors upon metabolic deterioration.

Relationship between fat distribution and lipid and apolipoprotein profiles in young teenagers.

The influence of obesity and fat distribution on serum levels of lipoprotein and apolipoprotein was investigated in 294 Japanese junior high school children (12-13 years of age). Serum levels of low-density lipoprotein cholesterol (LDLC) (P = 0.013), triglycerides (TG) (P = 0.0006), and apolipoprotein B (apoB) (P = 0.003), and the apoB/A-I ratio (P = 0.005) were significantly higher and serum levels of high-density lipoprotein cholesterol (HDLC) (P = 0.00003) and apoA-1(P = 0.003) were significantly lower in obese boys than in non-obese boys. The serum levels of TG (P = 0.013) and the apoB/A-I ratio (P = 0.011) were significantly higher and the serum levels of HDLC (P = 0.004) was significantly lower in obese girls than in non-obese girls. The LDLC/apoB ratio was lower in obese girls than in non-obese girls (P = 0.03). Obesity (> or = 20% of ideal weight) was strongly correlated with the serum levels of lipids and apolipoproteins in boys; this relationship was less clear in girls. The degree of obesity and the body mass index (BMI) were more strongly correlated with serum levels of lipids and apolipoproteins in boys than in girls. In boys, atherogenic lipoproteins and apolipoproteins, such as LDLC and apoB, showed a stronger correlation with the thickness of the triceps skinfold, while in girls the anti-atherogenic lipoproteins and apolipoproteins, such as HDLC and apoA-I, showed a stronger correlation with both the triceps and the subscapular skinfold thicknesses. In girls the relationships between the BMI and the degree of obesity and the thickness of the subscapular skinfold (S) thickness were similar to the relationships between those parameters and the triceps skinfold (T) thickness. In boys, these parameters showed a stronger correlation with the subscapular skinfold thickness than with the triceps skinfold thickness. The correlation coefficients for the relationships between skinfold thickness and lipid and apolipoprotein levels were similar to the coefficients for the relationships between skinfold thicknesses and the severity of obesity and the BMI. The distribution of central-type fat accumulation, which is indicated by the thickness of the subscapular skinfold, the S/T ratio and S-T value, was inversely correlated with the HDLC level in both boys and girls. The degree of obesity was strongly correlated with the atherogenic lipoprotein profile in boys, in part because the subscapular skinfold thickness was strongly correlated with the degree of obesity and the BMI. In girls, the correlations between indices of central-type obesity and atherogenic lipid and apolipoprotein profiles were stronger than in boys. These data suggest that childhood obesity may be an early cardiovascular risk factor.

Reduced 11β-hydroxysteroid dehydrogenase type 1 activity in obese boys

The incidence of childhood obesity and type 2 diabetes has reached epidemic proportions. Glucocorticoid excess causes central obesity and diabetes mellitus as seen in Cushing's syndrome. The 11beta-hydroxysteroid dehydrogenase type 1 enzyme (11beta-HSD1) regenerates active cortisol from inactive cortisone. Altered 11beta-HSD1 may cause tissue-specific Cushing's syndrome with central obesity and impaired glucose homeostasis. Clinical and laboratory characteristics, and anthropometric measurements were determined in 15 male and 6 female obese pubertal children (aged 12-18 years, Tanner stages 2-5). In addition, analyses of 24-h excretion rates of glucocorticoids were also performed in 21 age-, sex-, and pubertal stage-matched non-obese children using gas chromatographic-mass spectrometric (GC-MS) analysis. 11beta-HSD1 activity (urinary tetrahydrocortisol (THF) + 5alpha-THF/tetrahydrocortisone (THE) ratio) was lower in obese when compared with non-obese boys. In addition, obese children had a higher total cortisol metabolite excretion than non-obese children. 11beta-HSD1 activity was significantly related to age in lean and obese children. Standard deviation score (SDS)-body mass index did not correlate with 11beta-HSD1 activity, or with total cortisol metabolite excretion within each group. In obese children, 11beta-HSD1 activity and total cortisol metabolite excretion showed no correlation to waist-to-hip ratio, fat mass (percentage of body mass), or the homeostasis model assessment of insulin resistance index. In conclusion, our findings strongly suggest that 11beta-HSD1 activity increases with age, and is reduced in obese boys. In addition, obese children have a higher total cortisol metabolites excretion suggesting a stimulated hypothalamus-pituitary-adrenal axis.

Pedometer-determined Physical Activity among Obese and Non-obese 8- to 12-year-old Saudi Schoolboys

Physical activity levels were measured in obese and non-obese 8- to 12- year-old schoolboys (n=296). Anthropometric measures included weight, height, body mass index (BMI), triceps and subscapular skinfolds, predicted fat percentage, fat mass (FM), fat-free mass (FFM), FM index (FMI), and FFM index (FFMI). Physical activity was assessed using an electronic pedometer for three continuous weekdays. Boys were divided into active and inactive groups based on daily accumulation of pedometer counts above or below 13,000 steps. Obesity was defined as body fat content that equals or exceeds 25% of body weight. The international age- and gender-specific child BMI cut-off points were also used to define overweight and obesity. Estimated fat content for the whole sample averaged 23.3+/-9.7%. More than 37% of the boys were classified as obese. The mean step counts were about 13,489+/-5,791 steps per day (range: 335-29,169 steps). Over 71% of the boys accumulated 10,000 steps or more per day. Based on BMI standards, mean step counts for the obese group (10,602+/-4,800 steps/day) were significantly (p=0.004) lower than in the normal group (14,271+/-5,576 steps/day). Based on fat percentage, obese boys also accumulated significantly (p=0.009) lower numbers of steps per day (12,682+/-5,236) than did non-obese boys (14,915+/-5,643). Further, there were significant differences (p<0.05) between active and inactive boys in weight, BMI, triceps and subscapular skinfolds, fat percentage, FMI, and flexibility. It is concluded that the prevalence of obesity and inactivity among Saudi boys aged 8-12 years was high. Active boys exhibited significantly lower body fat percentage and BMI than inactive peers. Obese boys, on the other hand, were significantly less active than non-obese boys. Increased prevalence of obesity and physical inactivity among Saudi children is a major public health concern.